Example embodiments of the inventive concept relate to semiconductor devices. More particularly, example embodiments of the inventive concept relate to three-dimensional semiconductor devices and to methods of fabricating three-dimensional semiconductor devices.
Increased device integration is an important factor in realizing higher performance and lower cost semiconductor devices. In the case of two-dimensional (or planar) semiconductor memory devices (that is, memory devices in which memory cells are arrayed in a same plane), further integration is largely limited by the cost-effectiveness of available technologies for forming fine patterns in and on a semiconductor substrate. As pattern dimensions decrease, equipment costs can dramatically increase and the fabrication process can become cost-prohibitive.
In an effort to overcome such limitations, three-dimensional semiconductor memory devices are being developed in which the memory cells thereof are arrayed in three-dimensions over a substrate. However, in order achieve commercial viability, it will generally be necessary for three-dimensional semiconductor devices to equal the reliability and performance characteristics of their two-dimensional counterparts.